The problem is that these bots seem to seek out CS-Cart specifically because it is so weak.
So why are you still using CS-Cart if other carts have better solutions to this problem? There must be something else about the software that outweighs this huge shortcoming--and for you that is...what?
I was not specifically talking about carts but about many types of platforms from CMS, to forum, to cart. CS-Cart has a lot of addons, but nothing in this regard yet.
We have done a lot of custom development on CS-Cart. Quite a few addons on the marketplace were funded by us. Switching to a new platform is on the table, but would require custom development on another platform as well. Which means significant investment of time and money. Therefore any such switch would be a long term possibility. The vulnerability of CS-Cart would be one of many deciding factors. But I do not see that as something that cannot be resolved, but it requires an advanced addon from which pretty much any webmaster would benefit.
How do you even operate an online store under those circumstances? That sounds terrible.
It occurs for about a week once a month and when they start, I block the user agent. They use about 5 different user agents and the same ones each month. Yes, I know I could be blocking legitimate users but it's the only way since they are using hundreds of proxy IP's.